PREX1 and gastric cancer: However, since Prex1 is the exchange factor of Rac1, and based on the existing data of the article that the effect of Rac1 interference on gastric cancer cells is higher than that of Prex1, and the interference effect of the two genes is also obvious, while rTGF-β1 treatment can counteract the effects of both interference, this can also explain that the presence of recombinant TGF-β1 can activate EMT, and Rac1 and Prex1 are also closely related to EMT.